Phenolic polyethers

Polycondensations of 3,3-bis(chloromethyl)oxetane and a variety of bisphenols were studied using the microwave-PTC technique (Eq. 23) [35]. The results obtained showed the advantages of microwaves in terms of the molecular weights for crystalline polymer, as reflected in higher values of the transition temperature (Tg) and melting point (Tm) but also in reduction of reaction times for all types of structure. 

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It should be mentioned here that very interesting constitutional and translational isomerism is observed in the series of catenanes and rotaxanes which contain phenol derivatives such as macrocycUc phenylene-crown components as well as phenolic polyether chains (see also Lehn s recently published book ). 

Stearate soaps Dodecyl sulphate Dodecylbenzene sulphonate Dioctyl sulphosuccinate Nonyl phenol polyether sulphate Dodecyl polyether phosphate Polyethoxylated alkanol Polyethoxylated nonyl phenol Polyethoxylated polypropylene glycol (pluronic) Glyceryl monolaurate... 

Property AS TM test CeUul ose acetat b e Phenol. c 1C Extmded plank Expanded plank Extmded sheet PVC Polyether Bu g n Lamin ate... 

Fig. 3. Effect of density on compressive modulus of rigid cellular polymers. A, extmded polystyrene (131) B, expanded polystyrene (150) C-1, C-2, polyether polyurethane (151) D, phenol—formaldehyde (150) E, ebonite (150) E, urea—formaldehyde (150) G, poly(vinylchloride) (152). To convert...

Foams prepared from phenol—formaldehyde and urea—formaldehyde resins are the only commercial foams that are significantly affected by water (22). Polyurethane foams exhibit a deterioration of properties when subjected to a combination of light, moisture, and heat aging polyester-based foam shows much less hydrolytic stabUity than polyether-based foam (50,199). 

Poly- propylene poly- ethylene CAB" ABSf PVC Saran Polyester glass 1 Epoxy glass phenolic asbestos Fluoro- carbons Chlorinated polyether (Penton) Poly- carbonate... 

The first type includes vulcanising agents, such as sulphur, selenium and sulphur monochloride, for diene rubbers formaldehyde for phenolics diisocyanates for reaction with hydrogen atoms in polyesters and polyethers and polyamines in fluoroelastomers and epoxide resins. Perhaps the most well-known cross-linking initiators are peroxides, which initiate a double-bond... 

Moisture Deteriorating effects of moisture are well known as reviewed early in this chapter (OTHER BEHAVIOR, Drying Plastic). Examples for high moisture applications include polyphenylene oxide, polysulfone, acrylic, butyrate, diallyl phthalate, glass-bonded mica, mineral-filled phenolic, chlorotrifluoroethylene, vinylidene, chlorinated polyether chloride, vinylidene fluoride, and fluorocarbon. Diallyl phthalate, polysulfone, and polyphenylene oxide have performed well with moisture/steam on one side and air on the other (a troublesome... 

Chlorinated polyether is formulated particularly for products requiring, good chemical resistance. Other materials exhibiting good chemical resistance include all of the fluorocarbon plastics, ethylpentenes, polyolefins, certain phenolics, and diallyl phtha-late compounds. Additives such as fillers, plasticizers, stabilizers, colorants, and type catalysts can decrease the chemical resistance of unfilled plastics. Certain chemicals in cosmetics will affect plastics, and tests are necessary in most cases with new formulations. Temperature condition is also very important to include in the evaluation. Careful tests must be made under actual use conditions in final selection studies. 

An example for the synthesis of poly(2,6-dimethyl-l,4-phenylene oxide) - aromatic poly(ether-sulfone) - poly(2,6-dimethyl-1,4-pheny-lene oxide) ABA triblock copolymer is presented in Scheme 6. Quantitative etherification of the two polymer chain ends has been accomplished under mild reaction conditions detailed elsewhere(11). Figure 4 presents the 200 MHz Ir-NMR spectra of the co-(2,6-dimethyl-phenol) poly(2,6-dimethyl-l,4-phenylene oxide), of the 01, w-di(chloroally) aromatic polyether sulfone and of the obtained ABA triblock copolymers as convincing evidence for the quantitative reaction of the parent pol3rmers chain ends. Additional evidence for the very clean synthetic procedure comes from the gel permeation chromatograms of the two starting oligomers and of the obtained ABA triblock copolymer presented in Figure 5. 

Recently we have developed a new class of thermotropic liquid crystalline (LC) main-chain pol3rmers, i.e., polyethers of mesogenic bis-phenols(16-17.23-26). Since the obtained polymers are not soluble in dipolar aprotic solvents, the only available synthetic avenue for their preparation consists in the phase transfer catalyzed polyetherification. 

The reaction is generally carried out in the presence of a base such as sodium hydroxide. Bisphenol A is a phenol and, as such, a weak acid. The generated RO reacts with the electron-poor chlorine-containing carbon on epichlorohydrin, creating a cyclic ether end group. The phenoxy moiety can also react with the cyclic ether, eventually forming the polyether structure. This sequence is described in Figure 4.8. 

The primary resin of interest is epoxy. Carbon-fiber-epoxy composites represent about 90% of CFRP production. The attractions of epoxy resins are that they polymerize without the generation of condensation products that can cause porosity, they exhibit little volumetric shrinkage during cure which reduces internal stresses, and they are resistant to most chemical environments. Other matrix resins of interest for carbon fibers include the thermosetting phenolics, polyimides, and polybismaleimides, as well as high-temperature thermoplastics such as polyether ether ketone (PEEK), polyethersulfone (PES), and polyphenylene sulfide. 

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